freighter handling?

I don't have the skill to write mods but I've been puzzled by how the freighters handle in various mods?
why is it the freighter thay is knocked off course in a collision with smaller ships? it must outewigh them massively.
why can they not handle like the NPC versions seem to and why not the cargo hold?
seems to me if i was designing ships to venture in dangerous areas i would want a massive load to make it pay. (supertanker type) needs massive armour upgraded engines powerplants etc. or perhaps a very fast clipper type for very profitable high risk cargo, Ive not found that yet if it exists.
is it limiations of the game?